John Calvin Commentary Micah 6:12

"For the rich men thereof are full of violence, and the inhabitants thereof have spoken lies, and their tongue is deceitful in their mouth." — Micah 6:12 (ASV)

The Prophet means that the people were so given to greed and plunder that all the riches they had amassed had been acquired through wicked robberies or unjust gain. He now addresses the citizens of Jerusalem. For though wickedness then prevailed throughout all of Judea, there was still a reason why he should specifically accuse the inhabitants of Jerusalem: they must have led the way by their example, and they were also worse in their wickedness than the rest of the people. They were, at least, more stubborn, as they daily heard God’s Prophets.

Hence he says, her rich men gather not their wealth except by violence. It is indeed certain that the rich were not then alone guilty before God. But this evil has prevailed far too much: the more liberty anyone possesses, the more they use it to do wrong. Indeed, those who lack the power refrain, not because they are not inclined to do harm, but because they are, so to speak, restrained; for poverty often acts as a bridle to people. Since the rich could spread their snares and had the power to oppress the poor, the Prophet addresses his words to them—not because the rest were without fault or guilt, but because wickedness was more conspicuous in the rich, and that, as I have already said, was because their wealth gave them more power.

He afterwards extends his address to all the inhabitants: They all, he says, speak falsehood; that is, they have no sincerity or uprightness; they are entirely given to frauds and deceits. And their tongue is false in their mouth. This way of speaking seems, on its face, absurd, for where else can the tongue be but in the mouth? It appears then to be a kind of redundancy when he says that their tongue was deceitful in their mouth.

But this is an emphatic way of speaking, by which the Hebrews meant that people have falsehoods ready as soon as they open their mouths. It is, then, as if the Prophet had said that no pure word, free from deceit, could come from them. For as soon as they opened their mouths, falsehoods instantly came forth; their tongue was fraudulent, so that no one could expect any truth or faithfulness from these people. How so? Because as soon as they began to speak, they instantly revealed some deceit; there was always some falsehood ready to trick the unsuspecting.

So we now see that not just a few people were summoned before God’s tribunal, but that all, without exception, were condemned. It is as if the Prophet had said that there was no longer any integrity in the city and that corruptions prevailed everywhere, for all were intent on deceiving one another.